Geopsy project

Geopsy is both the name of a software project for seismology and geophysical applications and the name of the main application developed in this project. Geopsy project currently distributes all developed softwares under a package called 'Sesarray'. It contains several tools dealing with all the aspects of the processing of ambient vibrations for soil characterization. The main applications shipped inside 'Sesarray' are geopsy and dinver.

Geopsy project has been initiated during Sesame European research project thanks to a close collaboration between two groups from the Université Joseph Fourier (Grenoble, France) and the Universität Potsdam (Potsdam, Germany). It is now continuously improved and maintained by Marc Wathelet working at IRD-LGIT (Grenoble, France), and financed by European project NERIES.

Education

Since the end of year 2005, we have been organizing courses about ambient vibrations and related techniques based on the software products developed in this project. These courses extend over 5 to 6 days and gather about 15 to 20 participants. If you want to learn more about Geopsy and Dinver softwares, feel free to contact us. You can host a general audience course or we can organize a private training that fit exactly your requirements.

Products

General purpose

Applications

• figue: edition of figures extracted from other sesarray tools. Figures produced by figue are ready for publications (export to ps, pdf, jpeg, png, printer).
• geopsy: graphical user interface that accepts various wave formats, visualisation of waves and basic signal processing.
• dinver: inversion with Neighbourhood Algorithm modified after Wathelet (2008): surfave wave inversion,...

Libraries

• geopsycore: core routines of geopsy database (no reference to graphical user interface).
• geopsygui: graphical components for geopsy and geopsy plug-ins.
• scifigs: implementation of 2D plots and related widgets used in all tools, compatible with figue.
• Dinver plugins:
  • dinvercpp: basic skeleton that can serve as a base for the development of new inversion problems
  • dinverext: for inversion problems where direct computation is performed by an external application.
  • dinvermatlab: for inversion problems where direct computation is performed by Matlab (under development).
  • dinverfor: for inversion problems where direct computation is performed with Fortran.

Ambient vibration processing

Applications

• build_array: design of array geometry and computation of theoretical array responses.
• gpsignal: compute synthetic signals
• gpdc: computation of dispersion curves.
• gpell: computation of ellipticity curves.
• gpec8: determine site class from Vs profiles (Eurocode 8).
• gpgroup2phase: scan possible phase dispersion curves from a group dispersion curve.
• gpmodel2param: transform a model file into a parameterized ground structure
• gpparam2model: produce model files from parameter sets and a given parameterized ground structure.
• gppoisson: simple converter between Poisson's ratio, Vs, and Vp.
• gpprofile: extract Poisson's ratio, Vs, or Vp profiles from a model file.
• gpsh: computation of sh transfer curves (available but empty).
• gpspac: computation of autocorrelation ratio curves.
• gpsort: re-arrange curve order in a file (handy for gppac output).
• gprefra: computation of hodochrones (available but empty).
• gpprofile: output ground profiles from model files.
• gpdcreport: analysis of inversion report (from dinver).
• gpviewdcreport: plot inversion reports (from dinver).
• gpdcmisfit: recompute misfits of models produced by an inversion.
• spac2disp: tool for estimating the reliability of experimental auto-correlation curves.
• max2curve: tool for estimating the average and the uncertainties of a dispersion curve from FK or HRFK raw results.

Libraries

• qtbwave: computation of dispersion, ellipticity, and auto-correlation curves.
• qtbwavegui: graphical objects for qtbwave.
• qtbcompatibility: former qtbsurfacewave kept for file format compatibility.
• dinverground: library used by dinverdc that manage all ground models made of parameterized profiles.
• Geopsy plug-ins: directly linked to array analysis of ambient.
  • geopsyarray: array analysis of ambient vibrations (FK, High Resolution FK, MSPAC, FK for linear arrays)
  • geopsydamping: attenuation in buildings
  • geopsyhv: computation of H/V spectral ratios
  • structureratios: computation of spectral ratios for building structures
  • geopsyptmotion: particle motion
  • geopsynr: adjust time shifts and stack records of active source experiments (surface wave and refraction)
  • geopsytfa: time-frequency analysis using a Wavelet tranform.
  • geopsyrefra: computation of travel-time-distance curves for phase picking (to be modified for a better integration with dinver)
• Dinver plug-ins: plugins dedicated to ambient vibration processing:
  • dinverdc: surface wave inversion (including first P/S wave arrivals)

Third parties

• Qt 4 (included only in binary packages): the next generation Qt libraries for graphics on all platforms.
• f2c: to avoid troubles porting to all platforms, some remaining algorithms still in Fortran were automatically translated to C.
• fftw3: very fast implemetation of the Fourier transform.
• LAPACK 3.0: the reference library for Linear algebra.
• libslink: SeedLink protocol.
• libmseed: Miniseed reader.

References

Referencing these softwares is not an obligation, however, we would appreciate that you properly reference this work, released for free, in all your publications or reports achieved with these softwares. Here is a classified list of the papers published in the litterature closely linked to these softwares.

Frequency-wavenumber, high resolution, spatial autocorrelation techniques, wavenumber limits linked to array geometries

• Wathelet, M., D. Jongmans, M. Ohrnberger, and S. Bonnefoy-Claudet (2008). Array performances for ambient vibrations on a shallow structure and consequences over V_s inversion. Journal of Seismology, 12, 1-19. pdf.
• G. Di Giulio, C. Cornou, M. Ohrnberger, M. Wathelet, and A. Rovellii (2006). Deriving Wavefield Characteristics and Shear-Velocity Profiles from Two-Dimensional Small-Aperture Arrays Analysis of Ambient Vibrations in a Small-Size Alluvial Basin, Colfiorito, Italy. Bulletin of the Seismological Society of America, 96, 1915--1933. pdf

Specific to spatial autocorrelation technique

• A. Köhler, M. Ohrnberger, F. Scherbaum, M. Wathelet and C. Cornou (2007). Assessing the reliability of the modified three-component spatial autocorrelation technique. Geophysical Journal International, 168 (2), 779-796. pdf
• Wathelet, M. , D. Jongmans, and M. Ohrnberger (2005). Direct Inversion of Spatial Autocorrelation Curves with the Neighborhood Algorithm. Bulletin of the Seismological Society of America, 95, 1787--1800. pdf

Neighbourhood algorithm implemented in Dinver, dispersion curve inversion

• Wathelet, M. (2008). An improved neighborhood algorithm: parameter conditions and dynamic scaling. Geophysical Research Letters, 35, L09301, doi:10.1029/2008GL033256.pdf
• Wathelet, M., D. Jongmans, and M. Ohrnberger (2004). Surface wave inversion using a direct search algorithm and its application to ambient vibration measurements, Near Surface Geophysics 2, 211--221. pdf (NSG is not available online).